Recently, various techniques and products for obtaining a 3D image from a recognized object have been developed. For example, a TOF (Time Of Flight) system is to obtain a 3D image from a distance or depth between a camera and a recognized object, which is measured using a temporal difference between a light emission time for irradiating light to the recognized object and a light receiving time of light reflected from the recognized object. Also, a structure light system is to obtain a 3D image from a depth of a recognized object, which is measured by emitting patterned infrared structured light to the recognized object and analyzing a pattern of infrared rays received from the recognized object.
In this regard, although two or more visible light images may be used to obtain 3D depth information, a system, which uses the visible light images together with infrared ray images as an active light source, has been used recently. Also, in this system, it is general that a separate sensor (RGB sensor) for taking visible light is provided together with an infrared ray sensor (IR sensor). Furthermore, a camera sensor structure for obtaining visible light images and infrared ray images from one RGB-IR sensor by modifying one of sensor pixels for taking visible light to a pixel for obtaining infrared rays has been studied.